1. Field of the Invention
The present invention relates to a chronograph timepiece having a time indicating function and a time measuring function.
2. Description of the Related Art
Conventionally, there has been developed a chronograph timepiece in which a plurality of driving motors are mounted to respectively drive a plurality of hands and which is endowed with a time indicating function as a basic function and, further, a chronograph function to perform time measurement, wherein the driving of the hands is effected electrically by the driving motors, with the zero-restoring and setting of the chronograph hands being effected by a mechanical mechanism such as a heart (See, for example, JP-A-2005-3493).
In the invention as disclosed in JP-A-2005-3493, to prevent a malfunction, the following order is adopted in performing the zero-restoring operation: the input of a reset signal, the setting of a chronograph train wheel, and the zero-restoring (See paragraph [0030]); further, to eliminate a start error, the following order is adopted as the optimum timing in effecting the chronograph (time measurement) start: the releasing of zero-restoring or the releasing of setting, and a start switch input operation (See paragraph [0037]).
Accordingly, there are involved restrictions in terms of the switch input contact mechanism, so that the structures of levers and of switch springs are rather complicated.
Further, in a case where a reset operation is performed during the time measurement operation, if the setting is effected before a reset switch has been turned on to stop the hand movement, the motors cannot rotate, and the motor rotating positions and polarities stored in a motor drive circuit do not coincide with each other, with the result that the hand movement is impossible at the time of re-starting of the chronograph operation.
Further, in the chronograph start operation, if a start switch is turned on to start the motor driving before the setting has been released through a variation in the mechanism, the hand movement will be impossible even when the motors rotate. This problem is conspicuous when the hand movement cycle is short as in the case of a chronograph timepiece.